In svelte how to prefix paths for requests (dynamically)

[SpiderUnderUrBed]

So all of my routes are nested under /gameserver-rs, so requests will look like http://localhost:8080/gameserver-rs/index.html
I figured out a solution in my html code where I replace a meta tag with the base path, its important its not statically set and the server sets it, however svelte makes requests like:
GET
http://localhost:8080/_app/immutable/chunks/CNE7uOga.js

without gameserver-rs before app, so it fails with 404

IT NEEDS TO BE SET DYNAMICALLY. The server tells the client code where the base path is, I would perfer to not configure such a thing in a proxy, also paths or https://svelte.dev/docs/kit/$app-paths#base I dont think will work, because thats not dynamic, it'll statically set it.

(the reason why it needs to be dynamic is that this is supposed to be a self-hostable app, and with some proxies you would need to set a base path (e.g 192.168.68.77//))